CVE-2026-9516: Cpanel::JSON::XS versions before 4.41 for Perl allow denial of service via UTF-8 BOM prefixed input when a dec

Q: How do I fix CVE-2026-9516?

cpanel\: upgrade to 4.41. Exact commands for each OS are on this page.

Q: Is CVE-2026-9516 being exploited?

CVE-2026-9516 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-9516 affect?

CVE-2026-9516 affects cpanel\. Severity is high (CVSS 7.5). Cpanel::JSON::XS versions before 4.41 for Perl allow denial of service via UTF-8 BOM prefixed input when a decode filter callback throws. To skip a leading 3-byte UTF-8 BOM, decode_json() advances the input scalar's string pointer past the

Q: How urgent is CVE-2026-9516?

Priority 39/100. High severity; Remotely exploitable, no login, no user action

Routine

HIGH 7.5REMOTEUPGRADE

CVE-2026-9516 is a high-severity flaw (CVSS 7.5) affecting cpanel\. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Cpanel::JSON::XS versions before 4.41 for Perl allow denial of service via UTF-8 BOM prefixed input when a decode filter callback throws. To skip a leading 3-byte UTF-8 BOM, decode_json() advances the input scalar's string pointer past the mark with SvPV_set() and restores it only on the normal return path. When decoding aborts through a Perl exception, for example a filter_json_object callback that croaks, the restore is skipped and the scalar

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 70%)
CISA exploited list	No
Weakness	CWE-755, CWE-763
Published	2026-06-03
Last modified	2026-07-22

Publisher (CNA): CPANSec · Vendor: rurban

Last updated 2026-07-22 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-03 01:16 UTCPublished CVE record published
2026-07-22 19:10 UTCUpdated Record last modified

rurban cpanel\ UPGRADE

Affected: < 4.41

Fixed in: 4.41

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy cpanel || rpm -q cpanel || cpanel --version

2. UPGRADE to 4.41 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade cpanel

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade cpanel

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-9516?

cpanel\: upgrade to 4.41. Exact commands for each OS are on this page.

Is CVE-2026-9516 being exploited?

CVE-2026-9516 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-9516 affect?

CVE-2026-9516 affects cpanel\. Severity is high (CVSS 7.5). Cpanel::JSON::XS versions before 4.41 for Perl allow denial of service via UTF-8 BOM prefixed input when a decode filter callback throws. To skip a leading 3-byte UTF-8 BOM, decode_json() advances the input scalar's string pointer past the

How urgent is CVE-2026-9516?

Priority 39/100. High severity; Remotely exploitable, no login, no user action

Software pages

Perl vulnerabilities

Related CVEs

CVE-2026-9334 HIGH 7.3 UPGRADE Cpanel::JSON::XS versions before 4.41 for Perl allow type confusion via duplicate object keys when dupkeys_as_

References

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